Messages in this thread | | | Date | Tue, 17 Aug 2010 08:47:34 +0200 | From | Sascha Hauer <> | Subject | Re: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support |
| |
On Tue, Aug 17, 2010 at 07:36:12AM +0300, Baruch Siach wrote: > Hi Sascha, > > On Mon, Aug 16, 2010 at 04:15:40PM +0200, Sascha Hauer wrote: > > On Mon, Aug 16, 2010 at 02:21:06PM +0200, Linus Walleij wrote: > > > 2010/8/16 Sascha Hauer <s.hauer@pengutronix.de>: > > > > The SDMA engine is a scatter/gather DMA engine which is implemented > > > > as a seperate coprocessor. SDMA needs its own firmware which is > > > > requested using the standard request_firmware mechanism. The firmware > > > > has different entry points for each peripheral type, so drivers > > > > have to pass the peripheral type to the DMA engine which in turn > > > > picks the correct firmware entry point from a table contained in > > > > the firmware image itself. > > > > > > Quite fun, if the spec for the microcode is open this opens up > > > for dynamic firmware generation for specific DMA jobs does it > > > not? > > > > Unfortunately the specs are not open, so we are sticked to the binary > > microcode from Freescale. I'm pretty sure though that the SDMA engine > > could do at least a device_prep_dma_xor operation. > > Chapter 38 in the i.MX25 Reference Manual seems to include almost everything > there is to know about the SDMA. Isn't this enough for writing custom SDMA > microcodes?
Unfortunately not, the assembler is missing.
Sascha
-- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
| |